This invention is concerned with providing a pneumatically powered reversible impact wrench with improved manually operable torque selector mechanism which enables the operator to adjust and select the torque output value of the tool that may be needed in accordance with the work involved and the intended torquing direction.
A tool of this improved nature is especially desired in auto service stations in applying and removing bolts and nuts, some applications requiring transmission of full torque in a forward or reverse direction, and other applications requiring only limited torque in one direction or the other.
Accordingly, a general object of the invention is to provide a pneumatically powered reversible impact wrench with manually operable directional torque and torque value control means which enables the operator to select not only the direction of torque output but also to regulate the value of the output in either a forward or reverse direction.
Another object is to associate at a convenient location, as in the handle of the tool, an air flow regulating unit with a directional flow control valve in such manner that each is manually adjustable independently of the other and the adjustment of one does not interfere with adjustment of the other.
A further object is to provide in association with a flow by-pass valve a flow regulating valve which is manually selectively adjustable to cause restricted air flow through the by-pass valve, or to cause without further adjustment of the regulating valve full air flow through the by-pass valve following a relative adjustment of the latter.
A feature of the invention is a combined flow by-pass valve and flow regulator valve in association with a directional valve whereby the foregoing objectives are accomplished.
In accordance with the invention there is provided a pneumatically powered nut running tool comprising in a housing, a reversible rotary air motor for providing a forward or reverse torque output accordingly as live air is applied to a forward or reverse side of the motor; a throttle valve for admitting live air into the housing; a directional valve selectively manipulative for controlling the directional application of the live air to the motor, and a manually operable flow regulating unit positioned between the directional valve and the throttle valve for regulating the volume flow of the live air from the throttle valve to the directional valve, the regulating unit comprising a manipulative by-pass valve in sleeved relation to a separately manipulative regulating valve each being selectively adjustable relative to the other for determining either a full or a restricted volume air flow to the directional valve.